/*
n!=n*(n-1)*(n-2)*...*2*1
n由键盘输入
5 
5!= 120
*/
#include <stdio.h>
int main(){
    //1.存储阶乘的结果 fact
    //2.存储n
    //3.循环变量 i
    long fact=1;
    int n;
    int i;
    scanf("%d",&n);
    for(i=1;i<=n;i++){
        fact *= i;//fact = fact * i
    }
    printf("%d!=%ld",n,fact);
    return 0;
}
